Fibroblast-Derived Microfibrillar-Associated Protein 5 Exerts Cardioprotective Effects After Myocardial Infarction by...

Area of Science:

• Cardiovascular Biology
• Extracellular Matrix Research
• Cellular Signaling

Background:

• Myocardial infarction (MI) is a leading global cause of death.
• The role of microfibrillar-associated protein 5 (MFAP5) in cardiac function was previously unknown.
• This study investigated MFAP5's origin, expression, function, and mechanisms in MI.

Purpose of the Study:

• To determine the source and expression patterns of MFAP5 in the context of MI.
• To elucidate the functional role of MFAP5 in myocardial infarction.
• To uncover the molecular mechanisms by which MFAP5 influences cardiac cells during MI.

Main Methods:

• Single-cell analysis and immunohistochemistry for MFAP5 localization.
• MFAP5 knockout and cardiac fibroblast-specific overexpression mouse models.
• RNA sequencing, ingenuity pathway analysis, coimmunoprecipitation, and in vitro assays.

Main Results:

• MFAP5 expression is upregulated in human and mouse hearts during MI, originating from activated cardiac fibroblasts.
• MFAP5 deficiency worsened cardiac dysfunction and apoptosis post-MI, while fibroblast-specific overexpression was protective.
• MFAP5 inhibited cardiomyocyte apoptosis in vitro by activating NOTCH2 signaling.

Conclusions:

• Fibroblast-derived MFAP5 plays a crucial cardioprotective role following myocardial infarction.
• MFAP5 interacts with cardiomyocyte NOTCH2 receptors to prevent apoptosis.
• Targeting MFAP5 may offer a therapeutic strategy for MI recovery.